This invention relates to a shutter element to move between ON and OFF positions to selectively interrupt light from an optic fibre to a viewer. The combination of shutter and optic fibre can be used in an array for display or information purposes or individually as an indicator.
The shutter element may be combined with a fibre mount and a drive for the shutter newly designed for this purpose. However it may also be used to replace an ambient light disk in mountings previously designed for ambient light disks but modified to provide an optic fibre mount.
In the latter application it is noted that there are a number of designs for diametrically mounting a disk which is (usually) electromagnetically driven to display a light or a dark face to a viewer. Examples of such designs are:
U.S. Pat. No. 3,942,274 Mar. 9, 1976 PA1 U.S. Pat. No. 4,156,872 May 29, 1979 PA1 U.S. Pat. No. 4,243,978 Jan. 6, 1981 PA1 U.S. Pat. No. 4,577,427 Mar. 25, 1986 PA1 U.S. Pat. No. 4,860,470 Aug. 29, 1989
Such patents are commonly owned with this application. In such patents a disk is provided with pivotal mounting and rotated through, approximately 180.degree., to display a light or a dark side to the viewer. Thus the display or indicator depends on ambient light to illuminate the disk's bright side.
It is sometimes desireable to use optic fibres for display or indicator elements. Elements using such fibres usually require a shutter at the output end of the fibre to selectively provide the ON orientation (optic fibre radiation in the viewing direction) and OFF orientation (radiation interrupted in the viewing direction).